Feasibility of Quantitative value from bone scintigraphy for the evaluation of bone status in Chronic Kidney Disease-Mineral and Bone Disorders (CKD-MBD)

Introduction: The current study was designed to evaluate the potential role of quantitative analysis using bone scintigraphy for the assessment of bone status of chronic kidney disease-mineral and bone disorders (CKD-MBD). The current study was designed to evaluate the potential role of quantitative analysis using bone scintigraphy for the assessment of bone status of chronic kidney disease-mineral and bone disorders (CKD-MBD).

Methods: We retrospectively evaluated the patients with CKD (M : F, 70 : 52) who were evaluated with bone scintigraphy for the evaluation of CKD-MBD. The control data was also retrospectively recruited including 368 control subjects (M : F, 170 : 198) who have followed up with no evidence of disease state of the breast cancer for female and the prostate cancer for male for more 5 years. The quantitative indices were defined as the radiopharmaceutical uptake in skull, iliac bone and the ratio of the skull to the iliac bone (skull to iliac bone ratio, SIR). The bone mineral density (BMD) at the lumbar spine (LS), femur neck (FN) and total femur (TF) were acquired from dual energy X-ray absoroptiometry (DXA). Trabecular bone score (TBS) of LS was also calculated from DXA images. The clinical records of laboratory tests and underlying disease were reviewed retrospectively.

Results: The median TBS showed deteriorated state (median 1.276, interquartile range [IQR], 1.210 - 1.347 vs 1.302, IQR, 1.240 – 1.477, P < 0.005). Only 28 patients (23.0 %) had normal TBS in CKD patients, whereas 306 control (83.2 %) were normal state of TBS (P < 0.001). The count of the skull, iliac bone and SIR was significantly higher in CKD patients than the control. (median SIR 11.748*10³, IQR, 9.515*10³ – 14.428*10³ vs. 0.067*10³, IQR, 0.056*10³ – 0.087*10³, P < 0.001). The SIR had negatively correlation with values from DXA; LS (r = -0.300, P < 0.001); FN (r = -0.265, P < 0.001), TF (r = -0.264, P < 0.001) and TBS (r = -0.282, P < 0.001). The SIR also showed that significant correlations with levels of serum creatinine and bone ALP. The glomerular filtration rate did not have significant correlation with SIR. On the other hand, there was no significant correlation between SIR and DXA values and other biochemical results in control subjects. SIR was the remained as an independent variable for the significant correlation with levels of bone ALP in individuals with CKD using multiple regression.

Conclusions: The SIR has significant value for the diagnosis and metabolic status of CKD-MBD, especially in patients with high bone turnover state and may therefore potentially be used as an objective tool for the assessment of bone health in CKD patients.